feat: add typed conditional API responses

crates/api-macros/tests/ui/duplicate_response_header.rs

@@ -0,0 +1,14 @@
+use api_macros::api;
+
+pub struct Body;
+
+#[api]
+pub trait DuplicateResponseHeaderApi {
+    #[get(
+        "/duplicate",
+        responses = [(status = 200, body = Body, headers = [("etag", String), ("ETag", String)])]
+    )]
+    async fn duplicate(&self) -> duplicate_response_header_api_responses::Duplicate;
+}
+
+fn main() {}

crates/api-macros/tests/ui/duplicate_response_header.stderr

@@ -0,0 +1,5 @@
+error: duplicate response header name within one response
+ --> tests/ui/duplicate_response_header.rs:9:80
+  |
+9 |         responses = [(status = 200, body = Body, headers = [("etag", String), ("ETag", String)])]
+  |                                                                                ^^^^^^

crates/api-macros/tests/ui/invalid_response_header.rs

@@ -0,0 +1,14 @@
+use api_macros::api;
+
+pub struct Body;
+
+#[api]
+pub trait InvalidResponseHeaderApi {
+    #[get(
+        "/invalid",
+        responses = [(status = 200, body = Body, headers = [("bad header", String)])]
+    )]
+    async fn invalid(&self) -> invalid_response_header_api_responses::Invalid;
+}
+
+fn main() {}

crates/api-macros/tests/ui/invalid_response_header.stderr

@@ -0,0 +1,5 @@
+error: response header name must be a valid HTTP field name
+ --> tests/ui/invalid_response_header.rs:9:62
+  |
+9 |         responses = [(status = 200, body = Body, headers = [("bad header", String)])]
+  |                                                              ^^^^^^^^^^^^

crates/api-macros/tests/ui/not_modified_body.rs

@@ -0,0 +1,14 @@
+use api_macros::api;
+
+pub struct Body;
+
+#[api]
+pub trait NotModifiedBodyApi {
+    #[get(
+        "/not-modified",
+        responses = [(status = 304, body = Body)]
+    )]
+    async fn not_modified(&self) -> not_modified_body_api_responses::NotModified;
+}
+
+fn main() {}

crates/api-macros/tests/ui/not_modified_body.stderr

@@ -0,0 +1,5 @@
+error: status 304 cannot have a response body
+ --> tests/ui/not_modified_body.rs:9:32
+  |
+9 |         responses = [(status = 304, body = Body)]
+  |                                ^^^

crates/api-macros/tests/ui/undeclared_response_status.rs

@@ -0,0 +1,18 @@
+use api_macros::api;
+
+pub struct Body;
+
+#[api]
+pub trait UndeclaredStatusApi {
+    #[get(
+        "/status",
+        responses = [(status = 200, body = Body)]
+    )]
+    async fn status(&self) -> undeclared_status_api_responses::Status;
+}
+
+fn invalid() -> undeclared_status_api_responses::Status {
+    undeclared_status_api_responses::Status::Status201 { body: Body }
+}
+
+fn main() {}

crates/api-macros/tests/ui/undeclared_response_status.stderr

@@ -0,0 +1,14 @@
+error[E0599]: no variant named `Status201` found for enum `undeclared_status_api_responses::Status`
+  --> tests/ui/undeclared_response_status.rs:15:46
+   |
+ 5 | #[api]
+   | ------ variant `Status201` not found here
+...
+15 |     undeclared_status_api_responses::Status::Status201 { body: Body }
+   |                                              ^^^^^^^^^
+   |
+help: there is a variant with a similar name
+   |
+15 -     undeclared_status_api_responses::Status::Status201 { body: Body }
+15 +     undeclared_status_api_responses::Status::Status200 { body: Body }
+   |